Crank throw adjusting means



Nov. 9, 1965 A. F. GROLL 3,216,277

CRANK THROW ADJUSTING MEANS Filed April 22, 1963 4 Sheets-Sheet 1 "5: 4 I29 I28 i lm 22 .2 l-' l5 2| l3 l7 I9 I I4 '6 ll! I2! l I I "8 i "9 I22 INVENTOR. ALVIN F. GROLL Nov. 9, 1965 A. F. GROLL 3,216,277

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Nov. 9, 1965 GROLL 3,216,277

CRANK THROW ADJUSTING MEANS Filed April 22, 1963 4 Sheets-Sheet 3 I03 6 I04 I04 I04 A. I, we

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ALVIN F. GROLL .6 I BY aflornel s- United States Patent Ofiice 3,216,277 Patented Nov. 9, 1965 3,216,277 CRANK THROW ADJUSTING MEANS Alvin F. Groll, R0. Box 347, Napoleon, Ohio Filed Apr. 22, 1963, Ser. No. 274,754 8 Claims. (Cl. 74-600) This invention relates to adjustable cranks, and more particularly to improve means for varying the length of a crank arm to alter the throw of the crank.

Heretofore metal working machines such as punch presses and the like which perform repetitive operations on material fed in strip form have been provided with feeding mechanisms which synchronize the advance of the strip material into the working area of the machine with the machine operation such that the material is advanced intermittently at a time when the working faces of the machine are separated from the work upon which they are operating. It is also been known to drive such feeder mechanisms by means of a reciprocating rack operatively coupled, as by a crank, to the main drive shaft of the machine. Typical of the many forms of devices of this nature is that shown in A. F. Groll, United States Patent No. 2,728,571 which issued Dec. 27, 1965 for Strip Stock Feeders.

In the type of feeder referred to above, the advance of the strip stock is frequently determined by the stroke of the reciprocating rack. A number of expedients have been employed to adjust the length of this stroke, including that of adjusting the length of the crank arm which imparts reciprocating motion from the rotating drive shaft of the machine. Such adjustments ordinarily involve expedients such as positioning a crank pin on a throw block connected to the drive shaft in a manner to provide a given degree of eccentricity of the pin with respect to the axis of the drive shaft and journaling a drive rod to the crank pin so that reciprocation is imparted to the more remote end of the rod in accordance with the degree of eccentricity of the pin. Where precise feed lengths are desired, it is frequently necessary that much experimentation in the position of the crank pin on the throw block be undertaken before a satisfactory feed length is achieved, that which is adequate to avoid the overlap of work areas on the strip stock within the machine and yet not so great as to be wastful of material by producing excessive space between work areas on the strip stock. Efforts have been undertaken to provide means for adjusting the reciprocation stroke to a limited degree during the operation of the crank as by means of an intermediate linkage as shown in A. F. Groll, United States Patent 3,076,368 which issued Feb. 5, 1963 for Micro-Adjustable Strip Stock Feeder. In addition, mechanisms for affording a limited range of adjustment of the effective position of the crank pin on the throw block have been undertaken wherein flexible shaft drives extend from some stationary position such as the frame of the machine to the rotating throw block. Such constructions have been subject to mechanical wear which ultimately cause exces sive play and failure.

In view of the above, one object of the invention is to improve the means for varying the eccentricity of the journal coupling a throw block to a drive rod.

Another object is to facilitate the precise adjustment of the eccentricity of a journal between a throw block and drive rod while the throw block is driven through its path of rotation.

A further object is to provide a fluid pressure actuated drive for adjusting the degree of eccentricity of a bearing coupling a throw block to a drive rod.

General objects are to provide an inexpensive, rugged, easily-maintained and readily-adjustable journal coupling between a throw block and a drive rod which is of a construction utilizing relatively simple parts.

In accordance with the above objects, one feature of this invention resides in utilizing as a journal a sleeve member having an eccentric bore which in turn is journaled on a crank pin secured to a throw block. A course adjustment of the effective crank arm can be achieved by the degree of eccentricity of the crank pin with respect to the axis of rotation of the throw block and thereafter rotation of the sleeve eccentrically journaled on the drive pin can be adjusted to provide a further micro adjustment of the element journaled with the drive rod.

Another feature resides in providing the sleeve eccentrically journaled on the crank pin with a mechanically coupled worm wheel which in turn is selectively driven by a worm mounted on a shaft which can be rotated in either direction depending upon the direction of adjustment desired in the effective throw of the crank.

Another feature resides in a fluid drive for the shaft which drives the worm. This drive comprises a crank coupled to the shaft and a reciprocal piston actuated by fluid pressure and carried on the throw block for advancing the crank. An incidental feature of this combination involves a fluid clutch mechanism which selectively connects the crank to the drive shaft for the worm whereby paired drive systems may be applied to the shaft to enable it to be selectively driven in either direction of rotation about its axis.

The aforenoted objects and features together with additional objects and features of this system will be more fully appreciated from the following detailed description when read in conjunction with the accompanying drawings in which:

FIG. 1 is a side elevation of the upper portion of a press having a reciprocating drive rod for theactuation of a feeder mechanism coupled to its main drive shaft and shows a front view of the crank arm adjusting means of this invention;

FIG. 2 is an enlarged front view of the throw block, upper portion of the drive rod, and the crank arm adjusting means of this invention;

FIG. 3 is a side view taken from the right side of FIG. 2;

FIG. 4 is a sectioned elevation of the elements shown generally in FIGS. 2 and 3 taken along a line horizontally bisecting FIG. 2 through the axis of the crank pin with the throw block rotated clockwise degrees;

FIG. 5 is an end view of FIG. 4 partially sectioned along line 5-5 of FIG. 4 in the housing and broken away in other portions to show the crank arm adjusting mechanism of this invention;

FIG. 6 is a section of the swival providing the fluid conduits for actuating the drive mechanism in accordance with the illustrated embodiment of this invention as taken along line 66 of FIG. 4;

FIG. 7 is a section showing the eccentric sleeve on the primary crank pin of this invention as taken along line 77 of FIG. 4;

FIG. 8 is a schematic diagram of the actuating fluid circuit for the drive mechanism of the illustrative embodiment of the invention; and

FIG. 9 is a sectional view of a valve structure utilized on the ends of the drive cylinders to insure proper sequencing of the application of fluid pressure to the clutch actuating mechanisms and the drive cylinders for the drive illustrated in this invention.

The improved crank arm adjustment of this invention is shown as it is employed in a mechanically operated punch press. Such a press is usually constructed with a frame 11 such as shown in FIG. 1. A cr-ank shaft and connecting rod, not shown in the figure, are included in the upper portion of the press and are arranged to drive a punch carrier 12 which is of the nature of the crosshead carried in ways in the front upper face of the frame 11. The lower face of the punch carrier 12 is fitted to receive a chuck 13 in which various punches or other tools may be mounted. A bolster 14 is securely mounted from the bottom portion of the frame 11 in such position that it may support a die plate and die (not shown) in position to cooperate with a work punch (not shown) carried by the chuck 13.

A feeder assembly 15 for advancing strip stock into the working faces of the punch and die is represented in general form in FIG. 1. This feeder can be of the type shown in A. F. Groll, United States Patent 2,728,571 which issued Dec. 27 1955 for Strip Stock Feeders. It comprises a U-shape frame 16 in which feeder rolls 17 and 18 are mounted on heavy shafts (not shown). These rolls are rotated intermittently in timed sequence with respect to the reciprocation of the punch carrier 12 by the rotation of a drive shaft 19 coupled by means of spiral gears (not shown) to the shafts supportting feed rolls 17 and 18.

The drive shaft 19 within the limits of the frame 16 carries an over-running clutch and gear assembly (not shown) which meshes with a rack 21. The rack 21 is carried on a connecting rod 22 which at its upper end 23 is pivotally connected to an adjustable journal on throw block 24 mounted on the end of the crank shaft of the press. In accordance with this invention, the journal can be moved with respect to the crank shaft of the press to adjust the length of stroke of the rack 21. A rack guide 25 pivotally mounted on the drive shaft 19 or a bushing concentric therewith serves to hold the rack 21 in mesh with the gear of the drive shaft 19 even though the rack rod executes a connecting rod motion because of its connection to the throw block 24.

The operative connection between the rack 21 and the throw block 24 is by means of a crank arm mechanism embodying a micro feed adjusting device shown in detail in FIGS. 2 through 5. The throw block is provided with a groove 26 extending diametrically across the axis of rotation of the main operating shaft of the press. The groove has a truncated pyramid form with a wide base and a much narrower open slot at the surface of the throw block so that the diverging side walls are adapted to receive and retain a trunnion member 27 having a base 28 elongated along the length of the slot 26 and of truncated triangular form so that its sides closely fit the slot side walls. The base 28 of the trunnion contains a threaded bore 29 running along its major longitudinal dimension in which a screw 31 is threadedly received. The major body portion of the trnnion extends outwardly from the throw block 24 and sustains the elements providing the micro adjusting system of the invention and to journal the upper end 23 of the connecting rod 22 for reciprocating rack 21 so that the elfective throw arm is adjustable further on the trunnion in order to vary the eccentricity or throw and thus the stroke of the reciprocating rack.

Manual adjustment of the trunnion 27 in its position of eccentricity with respect to the main drive shaft 32 of the press is effected by the rotation of the screw 31 which is fixed in its longitudinal position within the groove 26 by suitable shoulders of known form, not shown. One form of lead screw adjusted trunnion is shown in Alvin F. Groll, United States patent application Ser. No. 234,581 filed Oct. 29,1962. In order to vary the position of the trunnion 27, rotation of the throw block 24 must be stopped and the screw 31 rotated. Small changes in the degree of eccentricity of the journal for the connecting rod 22 can be achieved while the machine is in operation by virtue of the mechanism of this invention which involves a micro adjusting device operatively associated with the trunnion 27.

The main body portion 33 of trunnion 27 extends outwardly from the base as a pin of circular cross section having its longitudinal axis parallel to the axis of rotation of the throw block 24. A sleeve 34 is mounted upon the body 33 of the trunnion coaxially thereof to provide a shoulder 35 between the throw block 24 and the mechanism carried by the trunnion. The outer surface of the major body portion of sleeve 34 is of right circular cylinder form and provides a bearing surface 36 upon which is journaled a sleeve 37. The sleeve 37 has an undercut portion 38 which is circular in section and eccentric with respect to the major longitudinal axis of pin 33 and provides a seat for the ball bearing structure 39 coupling the trunnion to the connecting rod 22. The bearing structure 39 is seated in a suitable socket 41 at the upper end 23 of rod 22 and is retained therein by retainer ring 43 set in a suitable circumferential groove 44. The bearing structure 39 is retained within the seat 38 on sleeve 37 by retainer ring 45 seated in a suitable circumferential groove 46. A flanged ring 47 is fitted within the hearing seat 41 to function as a grease retainer. This ring 47 is circular and concentric with the axis of eccentric portion 38.

Inasmuch as the undercut portion 38 of sleeve 37 is eccentric with respect to the major longitudinal axis of that sleeve, and inasmuch as that major longitudinal axis is coaxial when mounted on the trunnion with the major longitudinal axis of the primary crank pin 33 provided by the trunnion, rotation of the sleeve 37 with respect to the trunnion alters the eccentricity of the bearing structure 39 and thus the bearing ring 41 and the upper portion 23 of rod 22 on the throw block 24. Thus, when the maximum wall thickness of the undercut eccentric portion 38 is aligned with the radius from the axis of rotation of the throw block to the major longitudinal axis of the trunion, the micro adjustment of eccentricity of the effective crank arm is at its limits. If that heavy wall is at the outer end of the radius, the eccentricity is at its maximum micro adjustment for the screw adjusted position of the trunnion and if the thickest wall portion is between the axis of rotation of the throw block and the major longitudinal axis of the trunnion, the eccentricity of micro-adjustment is at its minimum. Variations in eccentricity will be available at positions intermediate those extremes with the nominal length of the throw of the crank as established by the screw positioning of the trunnion with respect to the rotational axis of the throw block when the wall portions of the undercut eccentric 38 of equal thickness lie on the radius from the axis of rotation of the throw block to the major longitudinal axis of the trunnion.

Rotation of the sleeve 37 on sleeve 34 and thus eccentric 38 with respect to trunnion pin 33 is accomplished by the worm wheel 48 integral with the sleeve 37 and formed on the flange 49 at the outermost end thereof. This worm wheel is driven by a worm 51 which in turn is supported on shaft extension 52 journaled in bearings 53 fitted within a counter-bored seat 54 of the housing 55 and a counter-bored seat 56 in a retainer or cap 57 closing the end of the housing and secured thereto by cap bolts 58 tapped into suitable holes in a boss 59 on the housing.

The shaft 52 is rotated to drive worm 51 and thus worm wheel 48 within housing 60 integral with housing 55 by means of cranks 74 and which can be selectively coupled to the shaft 52 by means of clutches 63 and 64 and are actuated from piston rods 65 and 66 coupled to pistons 67 and 68 within the cylinders 69 and 71 respectively. These pistons in turn are displaced by the application of fluid pressure to the cylinders to cause reciprocation of their piston rods 65 and 66. Each clutch structure 63 and 64 as best seen in FIG. 5 comprises a housing 72 and 73 which is rotatable with respect to the housing 55, by means of cantilever arms 74 and 75 integral therewith forming cranks. Each crank arm is bifurcated and apertured at 76 to receive a crank pin 77 and 78 which is also passed through a suitable aperture in a link 79 and 81 to which the piston rod 65 or 66 is secured as by a suitable threaded coupling and lock nut 82. Clutch plate 83 is keyed to drive shaft 52 by a key fitted into suitable keyways in the shaft and the plate. The clutch plate is faced with a friction material 84 whereby that material can be brought into frictional engagement with the end 85 of the housing cavity 72 such that the rotation of the housing imparts rotation to the clutch plate and the shaft 52. In order to effect this engagement of the plate and housing, the plate is shifted along the longitudinal axis of the housing by displacement of pressure plate 86 through the imposition of fluid pressure in the example, air, on the fiexible diaphragm 87 secured between the lip 88 of the housing and a cover 89. A cavity 91 within the cover receives air pressure through the passage 92 which terminates on its outer face with a suitable pipe tap for hose coupling 93. Air flows from the cavity 91 through the passage 94 to hose coupling 95 for purposes to be described with respect to the pneumatic circuit as disclosed in FIG. 8.

Each piston rod 65 and 66 passes through a bushing 96 and 97 in the lower end cap of its cylinder and is sealed with respect thereto as by a suitable O ring (not shown) in a manner well known in the art. The piston rod may .be secured to the piston body 67 or 68 by any suitable means and that body is sealed with respect to the walls of the cylinder in which it fits for sliding motion along those walls by means of 0 rings 98.

Since the micro adjustment of the effective crank arm length is bidirectional, it is necessary that means be pro vided for rotating shaft 52 and worm 51 in either direction. Accordingly, cylinder 69 performs useful work when its piston 67 is driven downward to rotate clutch housing 63 in a counterclockwise direction as viewed in FIG. 4, thereby rotating shaft 52 and worm 51 counterclockwise as viewed in FIG. 4. The piston 68 in cylinder 71 performs its effective work on an upward stroke which rotates the clutch housing 64 in a clockwise direction and thereby rotates shaft 52 and worm 51 clockwise to effect micro adjustments in the direction opposite that achieved by the Work of cylinder 69. In view of these opposed directions of drive, the piston in cylinder 69 is normally biased to the top of the cylinder by a suitable spring 99 embracing piston rod 65 between the inner face of the bottom of the cylinder and the bottom face of the piston while the piston in cylinder 71 is normally biased to the bottom of the cylinder when performing no work by means of a spring 101 embracing the piston rod 66 and extending between the outer face of the lower end of the cylinder and lock nut 82.

Each cylinder is arranged for oscillation around its upper end with a connecting rod motion in order to avoid any binding of the piston rod 65 or 66 during the reciprocating motion thereof. This pivotal mounting is provided by a pivot pin 102 journaled in a boss 103 on an upper portion of the gear housing 60 which is integral with the housing 55. The pin 102 is journaled in suitable apertures on spaced bosses 104 straddling the boss 103 and integral with the top cylinder cap. Each of the cylinders has its cylinder caps sealed to its cylinder wall by suitable tie rods 105 extending from the four corners of the upper cap to the four corners of the lower cap.

Air pressure to perform work in the cylinder 69 is applied above the piston 67 therein through passages in the upper cap 106. Conversely, in the cylinder 71 air pressure is applied below the piston 68 therein to perform useful work through passages in the lower cylinder cap 107. Accordingly the lower cap of cylinder 69 and the upper cap of cylinder 71 are of simple form and need be provided with no apertures except perhaps a bleeding port to permit any air entrapped behind the piston to be bled off during the displacement of the piston in its working direction.

The valve structure in the upper cap 106 of piston 69 and the lower cap 107 of piston 71 is shown in cross section in FIG. 9. It is formed in a boss 108 or 109 extending across the cap and integral therewith to form a casing having a longitudinal bore 111 transverse of the cap. Each end of the bore terminates with a suitable pipe tap 112 and 113 adapted to receive fittings, A reciprocating cylinder 114 closely fitting and slidable in bore 111 is biased to the left hand end of the bore 111 as viewed in FIG. 9 by means of spring 115. Cylinder 114 functions as a valve body to close the air inlet passage 116 to the passage 117 extending into the cylinder 71. Spring is retained within the cylinder by means of a threaded plug fitted into the end 118 while the displacement of the valve body 114 to the left is limited by the ends of the hose fitting 119 which is fitted into the end tap 112. When the valve body 114 is displaced to the left by spring pressure, air is permitted to escape from the cylinder through the passage 121 into the bore 111 in the area housing spring 115 and across that bore to the passage 122 to the outside air.

The purpose of this valve structure 108 and 109 is to insure the proper sequencing of the application of air pressure to the clutches and drive cylinders so that the clutch first engages itself with the shaft 52 and maintains that engagement while the drive cylinder displaces the piston and thereby operates the crank formed by clutch housing 72 or 73 in a manner to rotate shaft 52. This is accomplished by the air circuits shown in FIG. 8 wherein the application of pressure on air line 123 to the clutch 63 and diaphragm 87 on the right hand end of shaft 52 as viewed in FIG. 5 displaces the diaphragm to engage that clutch with shaft 52, and then passes the air by means of air line 124 to the check valve 108 formed by the housing in the cap of cylinder 69. This valve will not pass air to the cylinder until sufficient pressure is developed on diaphragm 87 to insure engagement of the clutch. When that threshold pressure is exceeded, the valve body 114 is displaced against the biasing force of the spring 115 to a position exposing air inlet 117 into cylinder 69 to displace the piston 67 downward against return spring 99, thereby rotating shaft 52 in a counterclockwise direction as viewed in FIG. 4.

The eccentric shown has been proportioned in practice to provide a one-quarter inch change in feed length by varying the throw circle for the drive rod. Each stroke of an air cylinder has been arranged to produce approximately a inch change in feed length. Accordingly, air can be admitted to the line 123 intermittently in a succession of operations until the strokes of piston 67 within cylinder 69 has effected the desired change in feed length.

If a change of feed length in the opposite direction is desired, however, the air should be fed to the cylinder 71 by means of air line 125 the pneumatic clutch 64 at the left side of FIGS. 2 and 5 to displace its diaphragm 87 and engage its crank 75 with shaft 52. Air is then passed by air line 125 to check valve 109 within the housing on the lower cap 107 of cylinder 71 to displace the piston 68 upward against the return spring 101 and rotate shaft 52 in a clockwise direction as viewed in FIG. 4.

Inasmuch as the throw block 24 carries the tunnion 27, eccentric 38 and the drive mechanism therefor through a circular path, means are provided for supplying air pressure to the cylinders and clutches through a swivel 127, best seen in FIGS. 4 and 6, containing passages for air in communication wit-h passages in the gear housing 60. The housing 60 encases worm wheel 48, worm 51 and shaft 52 as described above and, in addition, supports the cylinders from bosses 103.

Air is supplied in a controlled manner to separate lines 128 and 129 which are led from a stationary mounted dual control valve 130 through suitable clips 131 which are secured to connecting rod 23 and terminated at quick exhaust valves 132 and 133. The quick exhaust valves 132 and 133 are coupled to the swivel 127 by suitable threaded connections 134 and 135. The swivel 127 is closely fitted to the outer end of the circular cross sec tion of trunnion body 27 and is provided with radial bores 136 and 137 at positions spaced longitudinally along its length and communicating with connections 134 and 135.

The swivel 127 is made up of a sleeve portion 138 nad an end cap 139. A bearing assembly 141 is mounted 145 to insure a seal between the relatively rotating parts 27 and 127.

Trunnion 27 has a pair of longitudinal passages 149 and 151 which convey air from radial passages 146 and 147 respectively to radial passages 152 and 153 of the trunnion which register with radial passages 154 and 155 in gear housing 60. Registration of the trunnion and gear housing passages is assured by key 156. The outer ends of longitudinal passages 149 and 151 are closed by plugs 157 and 158 threaded therein. The interface between the trunnion 27 and gear housing 60 on both sides of each set of radial passages is sealed against air leakage by O-rings 159 in suitable grooves. Hose couplings 161 and 162 are secured by threaded connections in the housing body and in communication with air lines 123 and 125 to air clutches 63 and 64 respectively.

The retainer rings 142 and 143 cooperate to maintain the swivel 127 with its air couplings in appropriate registry with the air passages of the trunnion during its rotation with respect to the trunnion body 33. The remaining structure as illustrated in FIG. 4 including the sleeve 34, the worm wheel-sleeve-eccentric assembly 37 on the sleeve 34, the gear housing 60 with its associated parts, the drive cylinders 69 and 71, the clutches 63 and 64, and the various air lines and mechanical couplings are all retained in position on the trunnion by the nut 163 engaging a threaded shank portion 164 of trunnion body 33. When the elements are assembled and the trunnion base 28 has been appropriately positioned in the slot 26 by means of the rotation of screw 31, nut 163 is tightened down against the outer end of gear housing 60 to trans mit pressure along the axis of the trunnion and through the housing 60 and sleeve 34 thereby pulling the divergent faces of the trunnion base 28 against the sides of the slot 26 to lock them on the screw and fix the trunnion position on the throw block. In order to facilitate this locking action, the trunnion base is split in a plane defined by the screw axis and the axis of pin body 33 of the trunnion, whereby it tends to clamp and more firmly engage the screw 31.

In operation, the feeder is initially set up by loosening nut 163 and establishing the coarse adjustment of the length of throw of the crank by rotation of the screw 31 to shift the radial displacement of trunnion 27 with respect to the axis of rotation 171 of throw block 24. This adjustment is effected with the throw block stationary and can be done with respect to a suitable scale on the throw block or associated therewith. In the event the course adjustment is to be established experimentally by operating the machine the eccnetric 38 should be adjusted to its neutral position that is with the center of the journal 38 eccentrically mounted on the trunmion radially spaced from the axis of rotation 171 of the throw block the same distance as the center of the trunnion 27 from the axis of rotation ,171. Operation of the mechanism with this setting of the eccentric can be used to gauge the course setting of the trunnion. Thereafter the fine adjustment of the throw arm can be accomplished by rotation of the eccentric on the trunnion to bring its center either closer to the axis of rotation than the center of the trunnion where a reduction in throw is desired or moving it further from the axis of rotation than the center of the trunnion where an increase in throw is desired.

While the eccentric mounting of the journal on the trunnion can be adjusted in a number of ways where that journal is rotatable on the trunnion and eccentrically mounted thereon the adjustment during operation of the crank is particularly advantageous. Such adjustment can be effected by any means which would serve to rotate shaft 52. However the penumatic drive proposed is relatively simple and easily maintained and it avoids the need for mechanical couplings between the rotating and non-rotating elements.

Adjustment through the pneumatic drive and its controls can best be appreciated from reference to FIG. 8 together with FIGS. 2, 3, 4 and 6. JIC symbols have been employed in the pneumatic diagram of FIG. 8. Those symbols indicate that, for example in the case of the valve 132, when the pressure on line 128 exceeds that on conduit 149, the control is actuated through the air passage 172 within the valve to open the valve permitting air to flow from 128 to 149 and through the swivel body 127 to the line 123. When the pressure on conduit 149 exceeds that on line 128, the pressure in auxiliary path 173 within the valve transfers the valve so that air in conduit 149 is exhausted to atmosphere through a port represented by the arrowhead 174. A similar representation is provided for the quick release valve 133 between line 129 and conduit 151 wherein the auxiliary control conduits within the valve are designated as 175 from the supply side and 176 from the utilization side while the exhaust port is designated 177. Similarly a three way valve 130 is shown diagrammatically for blocking all air when centered as shown, or for coupling air from a source to either of lines 128 or 129 while the other is connected to an exhaust line 178. When the arrows on the left side of the symbol for 130 are aligned with the lines the sources is connected to 128 and when those on the right side are aligned with the lines the source is connected to 129. Symbols 108 and 109 represents the check valves and symbols 69 and 71 represent the cylinders containing the spring returned pistons.

Air is supplied from a suitable source 179 through line 181 to a filter 182, a pressure gauge 183, and a lubicator 184 to line 185 and three-way valve 130 which is positioned in some area conveniently accessible to the operator of the machine or a setup man whereby the throw of the crank arm and thus the feed increment can be readily adjusted. When the valve is in its central position no air is supplied to either of lines 128 or 129 from supply line 185. When the valve is shifted to the right, air from line 185 is passed to line 128 through valve section 186 and when the valve is shifted to the left, air is suplied from line 185 to line 129 through section 187. Thus the control valve 130 is capable of selectively applying driving pressure to the drive mechanism for micro adjustment of the effective crank arm length.

In FIG. 7 the eccentric is shown adjusted for its maximum throw. The course adjustment of the center 181 of trunion 27 along screw 31 establishes the basic length of the throw arm by virtue of the separation center 181 from the axis of rotation 171 of throw block 24. The inner and outer faces of sleeve 34 and the inner face of eccentric 38 are concentric with center 181. The outer face of eccentric 38 is circular in cross section but has its center 191 displaced outwardly of center 181 on the radial line between the axis of rotation 171 and center 181. This places the journal supported on the outer face of eccentric 38 at its maximum distance from center 171 and provides the maximum throw arm. Rotation of eccentric 38 around trunnion 27 reduces the radial separation of center 191 from axis 171 and reduces the throw arm. To rotate eccentric in a clockwise direction with respect to the trunnion, worm 51 is rotated in a counterclockwise direction as viewed in FIG. 4. counterclockwise motion is imparted by drive cylinder 69 when air pressure is applied to line 128. Thus valve 130 is shifted to the right in FIG. 8 to apply pressure to line 128. When the pressure achieves the required level valve 132 passes it through conduit 149 and the swivel 127 to line 123 and clutch 63. Ht 1? app ied to diaphragm 87 and through line 124 to check valve 108. Check valve 108 is set to open only when the pressure has reached a level in excess of that necessary to displace clutch plate 83 to a position coup i g housing 72 with shaft 52 as best seen in FIG. Af e clutch 63 is engaged, valve 108 admits air to cylinder 69 displacing piston 67 downward so that piston rod 65 carries clutch housing 72 and coupled shaft 52 in a counterclockwise motion.

When valve 130 is returned to its centered position to relieve the pressure on line 128, valve 132 couples conduit 149 to port 174 to relieve the pressure on clutch 63 and release the coupling between clutch 63 and shaft 52. The body 114 of valve 108 is returned to the left as viewed in FIG. 9 by the relief of pressure in line 124 to permit the air in cylinder 69 to escape through ports 121 and 122. Spring 99 returns piston 67 to the upper portion of the cylinder so that it can be driven another stroke if further adjustment is required. Thus repetitive operation of valve 130 will cause repetitive strokes of the piston to cause a step-by-step rotation of shaft 52, worm wheel 48, and integral eccentric 38.

If adjustment in the opposite direction is dictated valve 130 is moved to the left to operate clutch 64 and derive motion from cylinder 71 through an upward power stroke of rod 66 to cause step-by-step clockwise motion of shaft 52.

Having described the invention, I claim:

1. An adjustable connecting rod-throw block combination comprising a rotatable shaft, a throw block on said shaft and having an axis of rotation coincident with the axis of said shaft, a crank pin on said throw block, a sleeve having an eccentric longitudinal bore journaled on said crank pin, a journal on the outer surface of said sleeve radially of its longitudinal bore and said crank pin, said journal being secured to said connecting rod, a worm wheel integral with said sleeve and concentric with said crank pin and said bore, a worm engaging said worm wheel, a shaft extending axially from said worm Wheel, a clutch engageable with said shaft, a fluid pres-sure actuated engaging means for said clutch, a crank coupled to said shaft by said clutch, and a fluid pressure actuated piston to drive said crank.

2. A combination according to claim 1 including a fluid conduit to said clutch, a cylinder for said piston, a fluid conduit to said piston, a valve to control the application of pressure to said conduits and means to apply clutch engaging pressure to said clutch prior to the application of piston actuating pressure to said cylinder.

3. An adjustable crank arm comprising a rotatable shaft, a throw block on said shaft having an axis of rotation coincident with the axis of said shaft, a pin having an axis parallel to said axis of rotation and spaced radially therefrom, a circular bearing having an axis parallel to said axis of rotation mounted for rotation on said pin eccentric of said pin, a fluid actuated drive mounted on sald rotatable shaft for rotating said bearing with respect to said pm to alter the separation of said bearing axis from axis of rotation, a source of fluid under pressure, and a swiveled fluid coupling mounted on said pin between said source and said drive.

4. An adjustable crank arm comprising a rotatable shaft, 21 throw block on said shaft having an axis of rotation coincident with the axis of said shaft, a pin having an axis parallel to said axis of rotation and spaced radially therefrom, a circular bearing having an axis parallel to said axis of rotation mounted for rotation on said pin eccentric of said pin, a first cylinder mounted on said rotatable shaft, a first piston driven by the application of fluid pressure to said first cylinder to rotate said bearing in a first direction with respect to said pin, a second cylinder mounted on said rotatable shaft, a second piston driven by the application of fluid pressure to said first cylinder to rotate said bearing in a second direction opposite said first direction, and means to selectively apply fluid pressure to said cylinder.

5. A combination according to claim 4 wherein said fluid is applied to said cylinders by means of a swivel mounted for rotation on said pin and having fluid conduits individual to each cylinder in communication therewith.

6. A combination according to claim 4 including a first clutch for coupling said first piston in driving relationship to said bearing, and a second clutch for coupling said second piston in driving relationship to said bearing.

7. An adjustable crank arm comprising a rotatable shaft, a throw block on said shaft having an axis of retation coincident with the axis of said shaft, a pin having an axis parallel to said axis of rotation and spaced radially therefrom, a circular bearing having an axis parallel to said axis of rotation mounted for rotation on said pin eccentric of said pin, a fluid actuated drive mounted on said rotatable shaft, a fluid actuated clutch responsive to pressures of at least a first magnitude for coupling said drive to said bearing for rotating said bearing with respect to said pin, means for applying fluid at essentially the same operating pressures to said clutch and drive, and a pressure sensitive valve barring application of fluid pressure to said drive at all pressures below said first magnitude.

8. An adjustable connecting rod-throw block combination comprising a rotatable shaft, a throw block on said shaft and having an axis of rotation coincident with the axis of said shaft, a crank pin on said throw block, a sleeve having an eccentric longitudinal bore journaled on said crank pin, a journal on the outer surface of said sleeve and secured to said connecting rod, a worm wheel integral with said sleeve and concentric with said crank pin and said bore, a support secured to said crank pin and rotatable therewith with respect to said connecting rod, a worm engaging said worm wheel and having a longitudinal axis lying in the plane normal to the longitudinal axis of said crank pin, a second shaft extending from said worm along the longitudinal axis of said worm and journaled in said support, a motor mounted on said support and drivingly connected to said second shaft for translating output motion of said motor to rotation of said shaft around its longitudinal axis.

References Cited by the Examiner UNITED STATES PATENTS 892,623 7/08 Richards. 2,116,624 5/38 Garratt. 2,174,780 10/ 39 Dusevoir et al. 2,453,072 11/48 Johnson. 2,856,793 10/58 Budlong 74-600 3,090,250 5/63 Budlong 74-600 BROUGHTON G. DURHAM, Primary Examiner. 

1. AN ADJUSTABLE CONNECTING ROD-THROW BLOCK COMBINATION COMPRISING A ROTATABLE SHAFT, A THROW BLOCK ON SAID SHAFT AND HAVING AN AXIS OF ROTATION COINCIDENT WITH THE AXIS OF SAID SHAFT, A CRANK PIN ON SAID THROW BLOCK, A SLEEVE HAVING AN ECCENTRIC LONGITUDINAL BORE JOURNALED ON SAID CRANK PIN, A JOURNAL ON THE OUTER SURFACE OF SAID SLEEVE RADIALLY OF ITS LONGITUDINAL BORE AND SAID CRANK PIN, SAID JOURNAL BEING SECURED TO SAID CONNECTING ROD, A WORM WHEEL INTEGRAL WITH SAID SLEEVE AND CONCENTRIC WITH SAID CRANK PIN AND SAID BORE, A WORM ENGAGING SAID WORM WHEEL, A SHAFT EXTENDING AXIALLY FROM SAID WORM WHEEL, A CLUTCH ENGAGEABLE WITH SAID SHAFT, A FLUID PRESSURE ACTUATED ENGAGING MEANS FOR SAID CLUTCH, A CRANK COUPLED TO SAID SHAFT BY SAID CLUTCH, AND A FLUID PRESSURE ACTUATED PISTON TO DRIVE SAID CRANK. 